The present application relates to microbial decontamination arts. It finds particular application in conjunction with the sterilizing or disinfecting of medical, dental, surgical, mortuary, laboratory, and other equipment which comes in contact with the human body, particularly the interior of the human body. The invention also finds particular application in conjunction with the sterilizing or disinfecting of medical wastes as well as disposable medical equipment which has come into contact with the interior of the human body. It is to be appreciated, however, that the present invention will also find application in conjunction with the packaging and use of other liquids which outgas or emit gas or vapor during storage and shipment.
Heretofore, medical facilities have commonly used steam autoclave sterilization systems. Instruments and equipment to be sterilized or disinfected were transported to a central sterilizing facility where they were sterilized under the supervision of sterilizing room technicians. In a steam autoclave, which typically has a cycle time of one to two hours, the equipment was subject to superheated steam at high pressures. After an appropriate sterilizing duration, the autoclave was depressurized and cooled. One of the drawbacks of steam autoclave sterilization is that some equipment is damaged by high temperatures and pressures.
The same steam autoclave systems have also been used for sterilizing or disinfecting medical wastes. However, autoclave sterilization is relatively time consuming and expensive, particularly for waste materials.
Instruments and equipment which could not withstand the temperature and pressure of an autoclave were commonly sterilized with ethylene oxide gas. After the equipment was sealed in a sterilizing chamber, the highly toxic ethylene oxide was introduced under pressure and allowed to remain for a few hours, as was appropriate to the selected sterilizing cycle. After the sterilizing cycle, the equipment could not be utilized until the absorbed ethylene oxide was removed. This generally required about 12 to 16 hours in a vacuum or about 72 hours at ambient atmospheric conditions. In addition to the long cycle time, there is also concern with operator safety when working with the highly toxic ethylene oxide gas. Strict safety procedures must be followed to prevent inadvertent venting and breathing of the ethylene oxide gas.
Liquid sterilization systems have been used for equipment which could not withstand the autoclave or ethylene oxide systems. However, prior to the parent applications hereto, most such liquid sterilization was performed manually. The equipment was immersed in a vat or tank which was filled with the sterilizing solution, rinsed, and used. Frequently, non-sterile tap water was used as the rinse. The potential for operator error leads to concerns of sterilization assurance when equipment has been manually sterilized.
Liquid sterilants, such as iodine, have been used in medical waste disposal systems. More specifically, medical wastes have been ground with water to make a more readily disposable slurry. Bound iodine solutions were commonly added manually to kill pathogenic organisms. However, the manual addition of liquid iodine again led to sterilization or disinfection assurance questions.
Perhaps the most common technique for disposing of medical waste including syringes, laboratory equipment, culture medium, and the like has been incineration. The wastes were incinerated at sufficiently high temperatures that the pathogenic organisms were killed. However, incinerators tend to be sources of air pollution. Air pollution restrictions render the construction of new incinerators difficult and in some cases impossible. Because reducing the air pollution from existing incinerators tends to be very expensive and in many cases impossible, older incinerators are being closed.
In the above-referenced U.S. Pat. No. 5,037,623, liquid peracetic acid is stored in a sturdy plastic ampule that has a vent aperture positioned at its volumetric center. The ampule is filled just under half way full such that the surface of the liquid is below the vent aperture in any orientation of the ampule. In this manner, the liquid cannot block access to the vent aperture by vapors and gases in the space above the liquid. A semi-permeable membrane covers the aperture to prevent splashed liquid from escaping. Although successful, this ampule does have the drawback that it is about twice as large as the volume of liquid which it carries.
The present invention contemplates a new and improved packaging system and microbial decontamination procedure.